[kernel] Streaming ScopeBuilder

runtime/vm/kernel_binary.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 #if !defined(DART_PRECOMPILED_RUNTIME)
 
 #include "vm/kernel_binary.h"
 #include "platform/globals.h"
 #include "vm/flags.h"
 #include "vm/growable_array.h"
 #include "vm/kernel.h"
@@ skipping 69 matching lines @@
   // objects before reading the bounds.
   int length = reader->ReadListLength();
   EnsureInitialized(length);
 
   // Make all [TypeParameter]s available in scope.
   for (intptr_t i = 0; i < length; i++) {
     TypeParameter* parameter = (*this)[i] = new TypeParameter();
     reader->helper()->type_parameters().Push(parameter);
   }
 
-  // Read all [TypeParameter]s and their bounds.
-  for (intptr_t i = 0; i < length; i++) {
-    (*this)[i]->ReadFrom(reader);
+  if (length > 0) {
+    // Read all [TypeParameter]s and their bounds.
+    for (intptr_t i = 0; i < length; i++) {
+      (*this)[i]->ReadFrom(reader);
+    }
+    first_offset = (*this)[0]->kernel_offset_;
   }
 }
 
 
 NamedParameter* NamedParameter::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   StringIndex name_index(reader->ReadUInt());
   DartType* type = DartType::ReadFrom(reader);
   return new NamedParameter(name_index, type);
 }
@@ skipping 212 matching lines @@
 Field* Field::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   kernel_offset_ = reader->offset();  // Notice the ReadTag() below.
   Tag tag = reader->ReadTag();
   ASSERT(tag == kField);
 
   canonical_name_ = reader->ReadCanonicalNameReference();
   position_ = reader->ReadPosition(false);
   end_position_ = reader->ReadPosition(false);
   flags_ = reader->ReadFlags();
+  reader->ReadUInt();  // parent class binary offset (or 0).
   name_ = Name::ReadFrom(reader);
   source_uri_index_ = reader->ReadUInt();
   reader->set_current_script_id(source_uri_index_);
   reader->record_token_position(position_);
   reader->record_token_position(end_position_);
   annotations_.ReadFromStatic<Expression>(reader);
   type_ = DartType::ReadFrom(reader);
   initializer_ = reader->ReadOptional<Expression>();
 
   can_stream_ = (initializer_ == NULL || initializer_->can_stream()) &&
                 annotations_.CanStream();
 
   return this;
 }
 
 
 Constructor* Constructor::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
+  kernel_offset_ = reader->offset();  // Notice the ReadTag() below.
   Tag tag = reader->ReadTag();
   ASSERT(tag == kConstructor);
 
   canonical_name_ = reader->ReadCanonicalNameReference();
   VariableScope<ReaderHelper> parameters(reader->helper());
   position_ = reader->ReadPosition();
   end_position_ = reader->ReadPosition();
   flags_ = reader->ReadFlags();
+  reader->ReadUInt();  // parent class binary offset.
   name_ = Name::ReadFrom(reader);
   annotations_.ReadFromStatic<Expression>(reader);
   function_ = FunctionNode::ReadFrom(reader);
   initializers_.ReadFromStatic<Initializer>(reader);
 
   can_stream_ = annotations_.CanStream() && function_->can_stream() &&
                 initializers_.CanStream();
 
   return this;
 }
 
 
 Procedure* Procedure::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
+  kernel_offset_ = reader->offset();  // Notice the ReadTag() below.
   Tag tag = reader->ReadTag();
   ASSERT(tag == kProcedure);
 
   canonical_name_ = reader->ReadCanonicalNameReference();
   VariableScope<ReaderHelper> parameters(reader->helper());
   position_ = reader->ReadPosition(false);
   end_position_ = reader->ReadPosition(false);
   kind_ = static_cast<ProcedureKind>(reader->ReadByte());
   flags_ = reader->ReadFlags();
+  reader->ReadUInt();  // parent class binary offset (or 0).
   name_ = Name::ReadFrom(reader);
   source_uri_index_ = reader->ReadUInt();
   reader->set_current_script_id(source_uri_index_);
   reader->record_token_position(position_);
   reader->record_token_position(end_position_);
   annotations_.ReadFromStatic<Expression>(reader);
   function_ = reader->ReadOptional<FunctionNode>();
 
   can_stream_ = annotations_.CanStream() &&
                 (function_ == NULL || function_->can_stream());
@@ skipping 195 matching lines @@
 }
 
 
 VariableGet* VariableGet::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   VariableGet* get = new VariableGet();
   get->kernel_offset_ = reader->offset() - 1;  // -1 to include tag byte.
   get->position_ = reader->ReadPosition();
   get->variable_kernel_offset_ = reader->ReadUInt();
   get->variable_ = reader->helper()->variables().Lookup(reader->ReadUInt());
-  ASSERT(get->variable_->kernel_offset() == get->variable_kernel_offset_);
+  ASSERT(get->variable_->kernel_offset_no_tag() ==
+         get->variable_kernel_offset_);
   reader->ReadOptional<DartType>();  // Unused promoted type.
   return get;
 }
 
 
 VariableGet* VariableGet::ReadFrom(Reader* reader, uint8_t payload) {
   TRACE_READ_OFFSET();
   VariableGet* get = new VariableGet();
   get->kernel_offset_ = reader->offset() - 1;  // -1 to include tag byte.
   get->position_ = reader->ReadPosition();
   get->variable_kernel_offset_ = reader->ReadUInt();
   get->variable_ = reader->helper()->variables().Lookup(payload);
-  ASSERT(get->variable_->kernel_offset() == get->variable_kernel_offset_);
+  ASSERT(get->variable_->kernel_offset_no_tag() ==
+         get->variable_kernel_offset_);
   return get;
 }
 
 
 VariableSet* VariableSet::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   VariableSet* set = new VariableSet();
   set->kernel_offset_ = reader->offset() - 1;  // -1 to include tag byte.
   set->position_ = reader->ReadPosition();
   set->variable_kernel_offset_ = reader->ReadUInt();
   set->variable_ = reader->helper()->variables().Lookup(reader->ReadUInt());
-  ASSERT(set->variable_->kernel_offset() == set->variable_kernel_offset_);
+  ASSERT(set->variable_->kernel_offset_no_tag() ==
+         set->variable_kernel_offset_);
   set->expression_ = Expression::ReadFrom(reader);
 
   set->can_stream_ = set->expression_->can_stream();
 
   return set;
 }
 
 
 VariableSet* VariableSet::ReadFrom(Reader* reader, uint8_t payload) {
   TRACE_READ_OFFSET();
   VariableSet* set = new VariableSet();
   set->kernel_offset_ = reader->offset() - 1;  // -1 to include tag byte.
   set->variable_ = reader->helper()->variables().Lookup(payload);
   set->position_ = reader->ReadPosition();
   set->variable_kernel_offset_ = reader->ReadUInt();
-  ASSERT(set->variable_->kernel_offset() == set->variable_kernel_offset_);
+  ASSERT(set->variable_->kernel_offset_no_tag() ==
+         set->variable_kernel_offset_);
   set->expression_ = Expression::ReadFrom(reader);
 
   set->can_stream_ = set->expression_->can_stream();
 
   return set;
 }
 
 
 PropertyGet* PropertyGet::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
@@ skipping 894 matching lines @@
 
 
 VariableDeclaration* VariableDeclaration::ReadFromImpl(Reader* reader,
                                                        bool read_tag) {
   TRACE_READ_OFFSET();
   PositionScope scope(reader);
 
   VariableDeclaration* decl = new VariableDeclaration();
   // -1 or -0 depending on whether there's a tag or not.
   decl->kernel_offset_ = reader->offset() - (read_tag ? 1 : 0);
+  decl->kernel_offset_no_tag_ = reader->offset();
   decl->position_ = reader->ReadPosition();
   decl->equals_position_ = reader->ReadPosition();
   decl->flags_ = reader->ReadFlags();
   decl->name_index_ = StringIndex(reader->ReadUInt());
   decl->type_ = DartType::ReadFrom(reader);
   decl->initializer_ = reader->ReadOptional<Expression>();
 
   // Go to next token position so it ends *after* the last potentially
   // debuggable position in the initializer.
   TokenPosition position = reader->max_position();
@@ skipping 219 matching lines @@
 
   return program;
 }
 
 
 FunctionNode* FunctionNode::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   TypeParameterScope<ReaderHelper> scope(reader->helper());
 
   FunctionNode* function = new FunctionNode();
-  function->kernel_offset_ = reader->offset();  // FunctionNode has no tag.
+  // FunctionNode tag not read yet.
+  function->kernel_offset_ = reader->offset();
+  Tag tag = reader->ReadTag();
+  ASSERT(tag == kFunctionNode);
   function->position_ = reader->ReadPosition();
   function->end_position_ = reader->ReadPosition();
   function->async_marker_ =
       static_cast<FunctionNode::AsyncMarker>(reader->ReadByte());
   function->dart_async_marker_ =
       static_cast<FunctionNode::AsyncMarker>(reader->ReadByte());
   function->type_parameters().ReadFrom(reader);
   function->required_parameter_count_ = reader->ReadUInt();
   function->positional_parameters().ReadFromStatic<VariableDeclarationImpl>(
       reader);
@@ skipping 28 matching lines @@
 
 kernel::Program* ReadPrecompiledKernelFromBuffer(const uint8_t* buffer,
                                                  intptr_t buffer_length) {
   kernel::Reader reader(buffer, buffer_length);
   return kernel::Program::ReadFrom(&reader);
 }
 
 
 }  // namespace dart
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)